Metal-Insulator-Metal (MIM) capacitors have been widely used in functional circuits such as mixed-signal circuits, analog circuits, radio frequency (RF) circuits, dynamic random access memories (DRAMs), embedded DRAMs, and logic operation circuits. Conventional MIM capacitors were formed in interconnect structures. Since the interconnect structures include copper lines and copper vias formed of damascene processes, the formation of conventional MIM capacitors was integrated with the damascene processes. For example, a bottom electrode of a MIM capacitor may be formed in one of the metal layers in the interconnect structure, while the top electrode of the MIM capacitor may be formed between two metal layers.
Conventional MIM capacitors are formed at the same level as the via layers connecting overlying and underlying metal layers. As a result, no metal line can be routed in the metal layer immediately under the MIM capacitors and in the regions vertically overlapping the MIM capacitors. Otherwise, the capacitance values of the MIM capacitors may be adversely affected by the parasitic capacitors between the MIM capacitors and the nearby metal lines.